Granted Patent
Utility
US 4,240,462 · App. 05/971,003
Recessed valve
Inventor:
Norbert Bankstahl
Patented Case
View Patent ↗
Granted: Dec 23, 1980
Filed: Dec 19, 1978
Inventor
Norbert Bankstahl
Assignee (at issue)
Friedrich Grohe Armaturenfabrik GmbH & Co.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.